#include<stdio.h>
int Sum (int s,int e){
    int sum=0;
    sum=(s+e)*(e-s+1)/2;
    return sum;

}
int main(){
    printf("process id running\n");
    int start =1;
    int end =100;
    int result=Sum(start,end);
    printf("process id done,%d\n",result);
    return 0;}
 
